template<typename K, typename 
T, typename 
P, const char * F, bool D>
class dd::Entity_element< K, T, P, F, D >
Class to wrap an entity object. 
The Entity_element instances are intended used in registries to support classification of meta data. The Entity_element template points to an instance of some type, and also has a property member that is associated with the entity, as well as a key with which the object is associated.
- Note
 - The entity object ownership is decided by the relevant template parameter, see below.
 
- Template Parameters
 - 
  
    | K | A key type, e.g. a pair of strings.  | 
    | T | An entity type, e.g. an Object_table instance.  | 
    | P | A property type, e.g. an enumeration.  | 
    | F | Function to map from property to name.  | 
    | D | Boolean to decide ownership of wrapped object.  |